Density Flashcards – Cambridge IGCSE (9–1) Physics 0972 (Extended) (2026–2028)

What is density, and how is it related to mass $m$ and volume $V$?

Density is mass per unit volume: $\rho = \frac{m}{V}$

What equation gives mass $m$ in terms of density $\rho$ and volume $V$?

$m = \rho V$

What equation gives volume $V$ in terms of mass $m$ and density $\rho$?

$V = \frac{m}{\rho}$

What are two common units of density?

$\mathrm{kg/m^3}$ and $\mathrm{g/cm^3}$

How must mass and volume units relate to the density unit used?

They must be consistent with the density unit.

What equation relates density to mass and volume?

$\rho = \frac{m}{V}$

What must be true of the units used when calculating density?

They must be consistent.

How is the volume of a liquid measured for a density calculation?

Measure it in a measuring cylinder.

How is the mass of a liquid found using a container?

Subtract the mass of the empty container from the mass of the container with the liquid.

How is the mass of a regularly shaped solid measured?

Using a balance.

How is the volume of a regularly shaped solid determined?

Measure its dimensions and use the appropriate geometric formula.

How can a measuring cylinder be used to find the volume of an irregular solid that sinks?

Record the liquid level before and after fully immersing the solid. The increase in volume is the solid’s volume.

Besides comparing liquid levels, how can displacement be used to find the volume of an irregular solid that sinks?

Collect the displaced liquid and measure its volume.

How does an object's overall density relative to a liquid determine whether it floats, sinks or remains suspended?

• Less dense: floats
• More dense: sinks
• Equal density: can remain suspended

What must be true of the units before comparing an object's density with a liquid's density?

Both densities must be expressed in the same units.